JPH07314401A - Chain saw - Google Patents

Abstract

PURPOSE:To provide an oil pump of a chain saw which can prevent a power loss or a noise from being generated by obstructing metallic powder or dirt from being entered the inside of an oil pump by a backflow of oil, improves durability of the oil pump, has advantage from an economically point of view also and does not lower operation efficiency. CONSTITUTION:In a chain saw provided with an oil pump 1 which makes lubrication oil of a saw blade chain discharge through an opening groove 44 of a discharge pipe 40, it is comprised by providing back flow preventive walls 45, 45,... in the direction interrupting a flow of the oil from the bottom part 44a of the opening groove 44.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a chainsaw,
In particular, the present invention relates to a chain saw equipped with an oil pump for supplying lubricating oil to a saw blade chain.

[0002]

2. Description of the Related Art Generally, a chain saw is provided with an oil pump for smoothing the traveling of a saw blade chain, and lubricating oil is supplied to the saw blade chain. As a chain saw oil pump, a so-called rotary plunger type oil pump is used, in which a plunger that reciprocates in a cylinder that forms a pump chamber rotates about its central axis, and the rotation causes the plunger to reciprocate in the cylinder. At the same time, a technique in which the oil supplied from the oil pump is supplied from the discharge port of the discharge pipe to the oil supply port provided in the guide bar of the saw blade chain is, for example, the fairness of the applicant of the present invention. As described in Japanese Patent Laid-Open No. 5-18088, etc., it is well known in the past.

[0003]

In the conventional chain saw oil pump, for example, when the position of the oil pump is lower than the oil supply port of the guide bar, the oil pump is left for a while after the operation. In that case, the oil remaining in the discharge pipe may flow back into the oil pump. At the time of this reverse flow, iron powder on the surface of the guide bar, metal powder such as residual powder obtained by polishing a saw blade chain, and dust may be mixed into the oil and enter the oil pump. If the oil pump is restarted in this state, metal powder, dust, etc. will be caught between the oil pump cylinder and the plunger, which will cause power loss and noise, as well as damage surrounding parts and make them durable. However, there is a problem in that it causes various troubles such as markedly impairing the sex. Therefore, maintenance work such as extremely troublesome plunger and cylinder replacement must be performed frequently, which causes a problem of lowering work efficiency and higher cost.

The present invention has been made in view of such conventional problems, and its object is to prevent metal powder and dust from entering the oil pump due to the reverse flow of oil. A chain saw oil pump that can prevent power loss and noise, improve the durability of the oil pump, is economically advantageous, and does not reduce work efficiency. Is to provide.

[0005]

In order to achieve the above object, an oil pump for a chain saw according to the present invention is a chain saw equipped with an oil pump for discharging lubricating oil for a saw blade chain from an opening groove of a discharge pipe. It is characterized in that a backflow preventing wall is erected from the bottom of the opening groove in a direction that blocks the flow of oil. As a more preferable specific example, a filter provided at the most upstream part of the opening groove can be mentioned.

[0006]

[Operation] In the chain saw according to the present invention configured as described above, the oil remaining in the opening groove of the discharge pipe should remain in the oil pump between the end of operation of the oil pump and the restart of operation. Even if it tries to backflow, it is temporarily stored in the compartment formed by the backflow prevention wall, and the metal powder and dust mixed in the oil are collected by adhering to the inner surface of the opening groove, and further The oil is also filtered by and is prevented from entering the oil pump.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cutaway cross-sectional view of a main part of a chain saw according to an embodiment of the present invention, and FIG. Chainsaw saw blade chain (not shown)
The illustrated oil pump 1 for supplying lubricating oil to the is a rotary plunger type, and its casing 2 is arranged adjacent to a lubricating oil tank (not shown) of the body of the chain saw. There is. A drive shaft 4 of a prime mover (not shown) is rotatably inserted in the casing 2, and a worm 3 is fixed to the drive shaft 4 so as to rotate integrally therewith.

On the other hand, a plunger 6 having a worm wheel portion 5 meshing with the worm 3 is provided with the casing 2
It is provided rotatably and slidably in the axial direction in the internal space portion 7 formed in. The worm wheel portion 5 is made of a suitable synthetic resin material, and is coaxially integrally molded with the plunger 6 using a commercially available needle roller which is processed with a high precision with a suitable metal material. There is. A bearing 8 made of a cylindrical steel material is fitted and fixed in the internal space 7. One shaft portion 61 of the plunger 6 extending from the worm wheel portion 5 to one end side is extended in the axial direction, and the bearing 8 is formed.
The pump portion 20 of the oil pump 1 is configured by projecting from the portion. A notched portion 61a formed by additionally machining a needle roller used as the plunger 6 is provided at the tip end portion of the one shaft portion 61. On the other hand, the plunger 6 has a cam portion 62a formed of an inclined surface on the tip end surface portion of the other shaft portion 62 coaxially extending on the opposite side of the pump portion 20 with respect to the worm wheel portion 5.

A guide pin 12 projecting into the internal space 7 is planted in the casing 2, and the inner end of the guide pin 12 is the cam portion 62 of the plunger 6.
It is in abutting engagement with a. Further, a compression coil spring 22 is interposed between the inner end 8a of the bearing 8 and the worm wheel portion 5, and the compression coil spring 22 connects the cam portion 62a of the plunger 6 to the pin 12a. It is urged to press.

The pump portion 20 has an inlet opening 31 and an outlet opening 32, which are formed between the distal end portion of the plunger 6 and open into a pump chamber 30 formed on the circumferential wall portions opposed to each other in the diametrical direction. There is. The opening of the outer end 8b of the casing 2 is closed by fitting and fixing a stopper member 8c formed of an elastic material such as rubber in a liquid-sealed state. In the inlet opening 31, the pump chamber 30 is connected to a lubricating oil tank (not shown) by a flexible tube 25 fitted and connected in a liquid-sealed state to an inlet nipple 34 formed integrally with the casing 2. on the other hand,
The outlet nipple 35 formed integrally with the outlet opening 32 is connected in a liquid-sealed state to a cylindrical connecting portion 41 formed at an upstream end portion of a discharge pipe 40 described later.

Next, the details of the discharge pipe 40 will be described. FIG. 3 shows the discharge pipe 4 integrally formed of an oil-resistant synthetic rubber material or the like, which is connected to the oil pump 1.
0 is a perspective view showing the whole example of FIG. 0, and FIG.
FIG. 5 is a front view seen from the IV direction, and FIG. 5 is a sectional view taken along the line VV in FIG. The discharge pipe 40 of the illustrated example has a substantially U-shaped cross-sectional shape and a discharge pipe main body 42 having a boat bottom shape as a whole,
The upstream end of the discharge pipe body 42 (the oil pump 1
The outlet nipple 35 side).

The discharge pipe main body 42 has a peripheral wall defined by an exposed end surface 43 having a substantially elliptical shape, extends in the vertical direction, and has a tapered side wall with respect to the bottom portion 44a (see FIG. 5). 44 are formed. A plurality of backflow prevention walls 45, 4 made of plate-shaped tongue pieces are formed from the bottom portion 44a of the opening groove 44 in a direction orthogonal to the length direction (direction in which oil flows) (direction in which oil flow is blocked).
5, ... are erected. As can be seen from FIG. 5, the backflow prevention walls 45, 45, ...
4a is sealed, and a small gap (for example, about 1 mm) is provided between the exposed end face 43 and the extension of the exposed end face 43 so as not to hinder the flow of oil, so that the lubricating oil can be discharged. Further, a mesh filter 46 that does not hinder oil flow is provided at the upstream end of the opening groove 44 (on the side of the connection portion 41) to appropriately remove metal powder, dust and the like by filtration. The flow path in the connection part 41 is also
It is preferable to set the thickness to the minimum necessary and improve the backflow prevention effect.

The discharge pipe 40 constructed as described above
Is connected to the outlet nipple 35 of the oil pump 1 and communicates with the discharge side of the oil pump 1. Figure 1
As shown in FIGS. 2 and 2, the exposed end surface 43 of the discharge pipe 40 is pressed from behind by the main body portion of the chain saw (not shown), thereby overlapping with the mounting seat surface 51 of the guide bar 50 for guiding the traveling of the saw blade chain. The side plate 51a is closely attached in a liquid-sealed state, and the opening groove 4 is formed.
4 communicates with the oil supply port 53 of the guide bar 50 through an elongated opening 52 formed in the side plate 51a.

Next, the operation of the oil pump of the chain saw according to the embodiment of the present invention thus constructed will be described. When the worm 3 is rotated by a driving force from a prime mover (not shown), the worm wheel portion 5 meshing with the worm 3 is reciprocally moved in the axial direction together with the plunger 6 while rotating. This reciprocating motion is caused by the cam portion 62.
a within the range set by the guide pin 12 and the one of the shaft portions 6 of the plunger 6.
1 The volume of the pump chamber 30 is increased or decreased by the reciprocating movement of the tip portion. During this pump operation, during the suction stroke in which the volume of the pump chamber 30 increases, the outlet opening 32 is closed by the peripheral surface of the tip end of the plunger 6 without the notch portion 61a, but the inlet opening 31 is closed. The notch portion 61a formed at the tip of the one shaft portion 61 communicates with the inside of the pump chamber 30. Therefore, the lubricating oil in the lubricating oil tank causes the flexible pipe 25 and the inlet opening 31 to pass through. Through the pump chamber 30
Is sucked in.

On the other hand, during the discharge stroke in which the volume of the pump chamber 30 decreases, conversely, the one shaft portion 61 of the plunger 6 in which the position of the inlet opening 31 is changed by the rotation.
Although closed by the tip portion, the outlet opening 32 communicates with the pump chamber 30 by the cutout portion 61a, so that the lubricating oil in the pump chamber 30 flows from the outlet opening 32 into the opening groove in the discharge pipe 40. 44, and is discharged into the saw blade chain guide groove 55 through the oil supply port 53 of the guide bar 50 to lubricate the saw blade chain.

The oil remaining in the opening groove 44 of the discharge pipe 40 remains between the oil pump 1 and the time when the oil pump 1 is restarted.
May flow backwards. If metal powder such as iron powder adhering to the surface of the guide bar 50 or residual powder after polishing of the saw blade chain or dust is mixed into the oil and enters the oil pump 1 as described above, as described above. There is a risk of various problems. However, such metal powder, dust, etc., are prevented from flowing into the backflow prevention wall 4 provided in the opening groove 44.
The oil is once stored in a compartment formed by partitioning the opening groove 44 by 5, 45, ... And is filtered by the filter to enter the oil pump 1. Is blocked. In addition,
Since a plurality of backflow prevention walls 45 are provided, the guide bar 50
There is no problem even if the position of the oil supply port 53 changes depending on the type.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various designs can be made without departing from the present invention described in the claims. It is possible to make changes. For example, in the illustrated example, an example in which a rotary plunger type oil pump is used as the oil pump has been shown, but in addition, for example, a gear type or a diaphragm type oil pump may be used.

[0018]

As can be understood from the above description, according to the present invention, power loss and noise are generated by preventing metal powder, dust, etc. from entering the oil pump due to the reverse flow of oil. It is possible to prevent the above, and also improve the durability of the oil pump, and it is economically advantageous,
In addition, it is possible to prevent the work efficiency from decreasing.

[Brief description of drawings]

FIG. 1 is a broken cross-sectional view of a main part of a chainsaw according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view taken along the line II-II in FIG.

FIG. 3 is a perspective view of a discharge pipe of an oil pump applied to the present invention.

FIG. 4 is a front view as seen from the direction of arrow IV in FIG.

5 is a sectional view taken along the line VV of FIG.

[Explanation of symbols]

 1 ... Oil Pump 40 ... Discharge Pipe 44 ... Opening Groove 44a ... Bottom of Opening Groove 45 ... Backflow Prevention Wall 46 ... Filter

Claims (2)

[Claims] 1. A chain saw having an oil pump 1 for discharging lubricating oil for a saw blade chain from an opening groove 44 of a discharge pipe 40, wherein a backflow prevention is performed from a bottom portion 44a of the opening groove 44 in a direction in which the oil flow is blocked. A chainsaw characterized in that walls 45, 45, ... Are erected. 2. The filter 4 is provided on the most upstream side of the opening groove 44.
6. The chainsaw according to claim 1, wherein the chainsaw is provided.